Laying sod is a task which is time-consuming and labor-intensive. For major sod-laying projects, the sod is typically laid by dispensing sod from a sod roll held by a wheeled vehicle, i.e., by unrolling a supported sod roll as the vehicle traverses the ground area to be sodded.
Sod rolls are bulky, unwieldy things which are quite difficult to deal with in sod-laying operations. Furthermore, in most sod-laying jobs it is necessary to use a number of rolls, and this necessitates repeated loading and unloading of the sod-laying apparatus with one sod roll after another, making roll changeover a significant part of sod-laying operations.
Developments have been made in sod-laying equipment, including various roll-supporting sod-laying vehicles such as the "4818 Super Turf Installer" (or "WMI Installer") made by Woemer Manufacturing International of Elberta, Ala., the sod layers made by Mobile Track Vehicles of Berrien Springs, Mich., and the "SPI 2430" self-propelled sod layer made by Brouwer Turf Equipment of Dalton, Ohio. Devices such as these are intended for use by a single operator, operating either from a walk-behind position or from an operator's seat.
United States patents on sod-laying equipment include U.S. Pat. Nos. 5,307,880, 5,697,452, 4,890,801, 4,878,542, 4,754,815 and 3,982,711. The devices of the aforementioned commercial products and the devices disclosed in patents each have drawbacks or problems which heretofore have not been solved. U.S. Pat. No. 5,307,880 (Woerner) relates to the aforementioned commercial sod-laying vehicle apparatus of Woerner Manufacturing International with respect to which the instant invention is a particular improvement and advance. Such patent is referenced below because much of the vehicle disclosed therein provides the context for highly preferred embodiments of the instant invention.
Despite advances represented by the commercially-available equipment and patents, there has remained a need for significant innovative improvement in the field of sod-laying vehicle apparatus with devices for the roll pick-up and holding devices, without giving up the benefits of the advances achieved to date.
Certain prior art equipment, including the referenced Woerner Manufacturing International equipment, requires an insert bar or core or core-mounting tube and bar within the sod roll for pick-up and holding of the sod roll on the sod-laying apparatus. Significant operational disadvantages and problems exist for equipment requiring through-roll structures. Inefficiency is inherent in the need for the operator to leave his normal walk-behind or seated position and insert a through-roll structure through the sod roll or core before whatever pick-up steps are then taken. Job sites may become littered with core tubes, requiring collection and recycling. Furthermore, requiring through-roll structures for roll pick-up may rule out the use of coreless sod rolls.
Coreless sod rolls are available and some prior sod-laying equipment, such as the aforementioned Brouwer apparatus, picks up and holds sod rolls without the use of through-roll structures. However, such equipment has significant operational disadvantages and problems. While the arm-mounted long pointed cones of such Brouwer device engage the opposed ends of a sod roll along its axis for pick-up and support, the motions and roll-engaging actions of such arms and cones tend to significantly mess up and significantly damage the inner portions of the coiled sod of a sod roll. It has now been determined that this sod-roll damage and mounting difficulty is attributable to the lateral swinging nature of the cone-support arms, including the wide arcs through which such arms must swing about their lateral pivot points during insertion of the long pointed cones into opposed roll ends; i.e., the cones move in substantially off-axis directions and positions during insertion which can necessarily cause the aforementioned sod-roll damage. The lateral arm-swinging motion also can render the proper positioning of the vehicle for roll pick-up most difficult, once again contributing to improper roll mounting and sod-roll damage.
Still another problem with such Brouwer equipment arises due to the fact that it is a three-wheel vehicle, having a single rear ground-engaging wheel for steering and two tires positioned on an axis forward of the sod-roll axis; thus, such sod-laying vehicle has a very long overall front-to-rear dimension compared to other equipment. Such long dimension makes it very difficult to lay sod on smaller, tighter areas and on other than flat ground. Furthermore, on uneven ground the three-wheel arrangement has a tendency of tipping side to side or sliding sideways, making it difficult to accurately install a row of sod in alignment with, and without damaging, a previously-laid row.
In summary, there is a need for further innovation in sod-laying apparatus, and it is to solution of the aforementioned problems that this invention is directed.